mise à jour du 31 mai 2003
Proc Natl Acad Sci USA 2003; 100; 5497-502
Neural mechanisms of empathy in humans: a relay from neural systems for imitation to limbic areas
Carr L, Iacoboni M, Dubeau MC, Mazziotta JC, Lenzi GL
Contagious yawning: the role of self-awareness and mental state attribution Platek SMet al
Neural mechanisms of empathy in humans: A relay from neural systems for imitation to limbic areas Laurie Carr, Marco Iacoboni


Abstract : voir l'article
How do we empathize with others? A mechanism according to which action representation modulates emotional activity may provide an essential functional architecture for empathy. The superior temporal and inferior frontal cortices are critical areas for action representation and are connected to the limbic system via the insula. Thus, the insula may be a critical relay from action representation to emotion. We used functional MRI while subjects were either imitating or simply observing emotional facial expressions. Imitation and observation of emotions activated a largely similar network of brain areas. Within this network, there was greater activity during imitation, compared with observation of emotions, in premotor areas including the inferior frontal cortex, as well as in the superior temporal cortex, insula, and amygdala. We understand what others feel by a mechanism of action representation that allows empathy and modulates our emotional content. The insula plays a fundamental role in this mechanism.

The manifold nature of interpersonal relations: the quest for a common mechanism.

Gallese Vittorio - Intituto di Fisiologia Umana, Universita di Parma, Italy. website for pdf

Trans R Soc Lond B Biol Sci 2003 Mai 29;358(1431):517-28

It has been proposed that the capacity to code the 'like me' analogy between self and others constitutes a basic prerequisite and a starting point for social cognition. It is by means of this self/other equivalence that meaningful social bonds can be established, that we can recognize others as similar to us, and that imitation can take place. In this article I discuss recent neurophysiological and brain imaging data on monkeys and humans, showing that the 'like me' analogy may rest upon a series of 'mirror-matching' mechanisms. A new conceptual tool able to capture the richness of the experiences we share with others is introduced: the shared manifold of intersubjectivity. I propose that all kinds of interpersonal relations (imitation, empathy and the attribution of intentions) depend, at a basic level, on the constitution of a shared manifold space. This shared space is functionally characterized by automatic, unconscious embodied simulation routines.

Functional imaging of theory of mind: the role of the STS Gallagher HL. Trends in Cognitive Scie 2003; 7; 2; 77-8

Emotion gets physical by Laura Spinney
Preliminary observations of stroke patients with problems relating emotionally to others suggest that in order to feel empathy, people must be able to imitate the actions of others. In other words, to understand what others are feeling, you must put yourself physically in their shoes.
Stroke can damage any area of the brain, but the patients in question all have lesions to one particular brain structure - the insula, which lies between the frontal and temporal lobes on both sides of the brain.
On tests of their ability to gauge the emotions being experienced by people from their facial expressions in photographs, these patients perform very poorly compared to healthy controls.
The study, which is being carried out by neurologist Gian Luigi Lenzi and his colleagues at La Sapienza University in Rome, Italy, is preliminary because damage to the insula in the brain's left hemisphere can also extend to language areas, affecting the patient's ability to communicate and hence potentially masking any separate, emotional impairment.
But if the insula does turn out to be the key to their emotional deficit, it would fit very well with data that Lenzi and his collaborators at the Ahmanson-Lovelace Brain Mapping Center at the University of California, Los Angeles published last month in the Proceedings of the National Academy of Sciences, on the neural correlates of empathy.
They scanned people's brains using functional Magnetic Resonance Imaging while they either observed or imitated images of facial expressions of emotion. In both tasks, they found activation of the limbic system, which is key to the processing of emotion.
But in the imitation task, they also found activation of the brain's mirror or imitation circuit, which is stimulated both by the observation and execution of an action, and of the insula. The limbic system was also significantly more active during this task.
According to one of the UCLA researchers, Marco Iacoboni, the findings suggest that empathy, or the ability to feel the emotions of others, is correlated with the degree to which one mimics their behavior.
The findings contradict the longheld view that an intellectual, computer-like brain generates empathy within itself, suggesting instead that "a brain needs a body to understand other brains," he says. And they also support behavioral studies relating to the phenomenon of emotional contagion, or the chameleon effect, in which people unthinkingly adopt the postures and mannerisms of those around them.
"People who tend to subconsciously and automatically imitate the postures and mannerisms of other individuals also tend to be concerned about the feelings of other people," said Iacoboni.
He thinks that the insula could play a pivotal role in this imitation-empathy mechanism, relaying information from the mirror circuit to the limbic system. In terms of its location in thebrain and its connectivity, he thinks it is ideally placed to do so. Although empathy is a complex phenomenon, he believes that a kind of "emotional resonance" might be a first step towards it, that is achieved through imitation and the activity of the insula. By teaching autistic children to imitate the expressions of others, he speculates that it might be possible to encourage them to develop the emotional understanding of others, which they lack - this will be the goal of his next research project.
But Jonathan Cole, a clinical neurophysiologist at Poole Hospital in Dorset, UK, is dubious. He has studied patients with Möbius syndrome, who congenitally lack facial expression. Although other studies have produced conflicting results, he says that his work suggests that the ability of such patients to recognize emotional facial expressions in others is "not that bad."
Andrew Meltzoff, a developmental psychologist at the University of Washington's Center for Mind, Brain and Learning in Seattle, says the UCLA group's work is "admirable", but that it is important to distinguish between emotional contagion and true empathy, which is different in that it involves the capacity to hold both your own emotional state and another's simultaneously - rather than to just "catch" their emotion and feel it as your own.
He believes, on the basis of his research in infants, that emotional contagion precedes empathy in developmental terms. And that preceding both of these, in the very youngest newborn babies, is the ability to imitate another's actions and expressions.
"Neuroscience has not fully cracked the brain basis of the mature adult feelings of empathy, but we are getting close," said Meltzoff. Image caption - 3D image of the brain seen from below. Three solid objects correspond to the posterior part of inferior frontal cortex, a mirror area important for imitation (green), the anterior insula (blue), and the amygdala, one of the emotional centers of the brain (yellow). Kindly provided by Marco Iacoboni, UCLA.

Characterization of Empathy Deficits following Prefrontal Brain Damage: The Role of the Right Ventromedial Prefrontal Cortex
Shamay-Tsoory, S. G., R. Tomer, et al.
J Cogn Neurosci 2003; 15; 3; 324-37

Impaired empathic response has been described in patients following brain injury, suggesting that empathy may be a fundamental aspect of the social behavior disturbed by brain damage. However, the neuroanatomical basis of impaired empathy has not been studied in detail. The empathic response of patients with localized lesions in the prefrontal cortex (n = 25) was compared to responses of patients with posterior (n = 17) and healthy control subjects (n = 19). To examine the cognitive processes that underlie the empathic ability, the relationships between empathy scores and the performance on tasks that assess processes of cognitive flexibility, affect recognition, and theory of mind (TOM) were also examined. Patients with prefrontal lesions, particularly when their damage included the ventromedial prefrontal cortex, were significantly impaired in empathy as compared to patients with posterior lesions and healthy controls. However, among patients with posterior lesions, those with damage to the right hemisphere were impaired, whereas those with left posterior lesions displayed empathy levels similar to healthy controls. Seven of nine patients with the most profound empathy deficit had a right ventromedial lesion. A differential pattern regarding the relationships between empathy and cognitive performance was also found: Whereas among patients with dorsolateral prefrontal damage empathy was related to cognitive flexibility but not to TOM and affect recognition, empathy scores in patients with ventromedial lesions were related to TOM but not to cognitive flexibility. Our findings suggest that prefrontal structures play an important part in a network mediating the empathic response and specifically that the right ventromedial cortex has a unique role in integrating cognition and affect to produce the empathic response.